Medical procedures include surgical, dental and health treatments. Medical procedures are performed either manually or with the assistance of supportive technologies for the enhancement of data collection, examination, visualization, or dexterity.
Medical treatment procedures such as surgeries and dental implants are carried out mostly manually, wherein the medical professional manipulates surgical tools for performing complex surgical and restoration procedures. The procedures can also be performed manually but with the help of a variety of supportive technologies that augment the professional's ability to examine the patient and observe the conditions of the ailment.
The professional relies on his or her medical expertise, manual dexterity, and hand-eye coordination skills to perform the procedures. Such skills and expertise vary widely among professionals and the results of the procedures are not always equivalent. To improve the success rate of a procedure, the professional makes use of data from laboratory and physical tests, detectable characteristics and by observation. X-rays provide visual details unavailable to the naked eye. Such data helps the professional decide on a treatment approach that, in his or her professional judgment, is best for the patient; that is not usually verified until after the procedure is completed with occasional unfortunate surprises.
To enhance the chances of success, new technologies have been developed that augment the professional examination capabilities, collect more supportive data for the procedure, improve over the dexterous skills of the professional and greatly enhance the hand-eye coordination. Vision systems utilizing video cameras, some miniature, can provide visual observations in tight locations and often are inserted into the human body cavities for real time examinations and collection of otherwise inaccessible information. Alternatively, technology has developed that often separated the professional from the patient. The professional's vision is augmented by tiny video cameras inserted into the treatment space. Dexterous skills are augmented by inserting miniature manipulators into the treatment space to manipulate the instruments. The cameras and the instruments are remotely manipulated by the professional with access to a magnified view of the tiny treatment space and controlled resolution for hand movements.
A well-known navigation guided surgical system, the da Vinci® Surgical System available from Intuitive Surgical of Sunnyvale, Calif., has been very successful in aiding surgeons perform complex minimally invasive procedures. With that system, complex surgeries are performed by remotely manipulating several surgical instruments inserted into the human body through minimal surgical cuts and attached to multi-axis computer controlled manipulators. It utilizes remotely controlled robotic arms carrying surgical instruments and visualization cameras that are manipulated by the surgeon from a remote control console. It provides enhanced visualization of the treatment space and better operational dexterity by beneficially utilizing digital scaling of images and instrument movements. It has enabled many procedures to be performed more successfully with less exposure to trauma by the patients.
Surgery could even be performed from remote locations by communicating the images of the work space in real time to distant locations where a surgeon can remotely guide and manipulate a surgical tool that is attached to a computer controlled manipulator.
Recently, surgical procedures have benefitted from new advances in imaging of the treatment space, computerized solid modeling technique and interactive graphics. The treatment space can now be scanned, digitally modeled, projected at a larger scale, and visualized from angles almost inaccessible to conventional visualization means. The surgical procedures can be pre-planned by interactively manipulating digitized virtual models of the treatment space and recording a desired procedure. Critical progress parameters can be displayed to guide the medical professional through the surgical process as described in the U.S. Pat. No. 6,640,128 B2 (the '128 patent). Tiny video cameras can be strategically located to monitor the treatment space, display the progress of the procedure, or identify deviations from the pre-planned course; this also allows multiple professionals to observe and monitor the procedure's progress.
3-dimensional images are virtual models of an object or a space that can also be stored with attributes that allow projection and manipulation of the images on a display to be viewed from any desired angle. Interfaces are provided for interactive input devices to help modify or augment the model with additional information such as tracing a path for a tool or displaying specific characteristics of the model. The virtual model could also be communicated to computer controlled machine tools that extract data necessary for the fabrication of certain parts of the model (impression of a jaw) or can be complementary to certain model parts (crown for a tooth).
The applications described above utilize computer controlled manipulators that are responsive to manipulation commands initiated by the medical professional. The manipulators do not utilize the ability of a robot to perform autonomous operations and are dependent on continuous interaction by the professional. In a manner similar to a machine tool, a robot was demonstrated at the University of California, Santa Cruz, Bionics Lab, spring 2011, for the milling of a model tooth in preparation for the addition of a crown; that was not a medical application as much as a demonstration of machining by a robot rather than by a conventional machine tool.
A method and device for navigation-assisted dental treatment is described in the '128 patent, wherein an image of the treatment space is generated and displayed on a screen monitor to provide visual guidance to the dentist before, during, and after the procedure. Cameras are also provided to track markers in the treatment space as well as the dental instruments and help the dentist in visualizing their relative locations on the large screen instead of the confined space of a human jaw. The desired path of the treatment instrument is also displayed together with the actual path traced by the dentist and a warning signal is generated when the two paths deviate. The '128 patent also recognizes that a robot can be used to guide the instrument during the treatment; the instrument's location is registered, tracked and controlled by the system.
However, the '128 patent is limited to “navigation assisted dental treatment” and does not extend to relieving the dentist from performing manual or dexterous operations. The imaging system serves to provide visualization of the treatment space and the relative position of the instruments during the process and leaves it to the dentist to manipulate the instruments. The procedure is then still subject to the limitations of the dentist's skills and dexterity. It teaches no autonomous operation. It teaches that the tracking system tracks the position of the instrument during the procedure and warns when the location deviates from a desired path; it displays a corrected path but leaves it to the dentist to respond. The '128 patent also recognizes the use of a robot “which fully or partly guides the instrument, is registered and/or referenced in the navigation and/or tracking system and positionally tracked, and is controlled by the system”, but it does not teach the source of information that the robot is guided by and does not relate it's operation to the digital data set of the treatment space.
Image-guided navigation in restorative dentistry and oral maxillofacial surgery: Dental imaging systems have been used to generate a virtual image of the treatment space, the jaw, and the teeth that is utilized to plan for the treatment and the fabrication of prosthetic devices such as crowns and implants. Such imaging systems today can be exemplified by commercially available products such as: the NobelGuide system available from Nobel Biocare USA, LLC of Yorba Linda, Calif.; the Anatomage imaging software available from Anatomage Inc. of San Jose, Calif.; Sirona CEREC CAD/CAM system available from Sirona Dental Systems LLC of Charlotte, N.C.; the Lava COS system available from 3M ESPE of St. Paul, Minn.; the iTero imaging system available from Align Technology, Inc. of San Jose, Calif.; and the TRIOS Digital Impression Taking Solution from 3Shape A/S, Copenhagen, Denmark.
For example, the image can be communicated to a milling machine or a 3 D printer for the fabrication of a mold or an artificial tooth, a crown or bridge. Currently, on-site and off-site milling capabilities are available from commercial entities such as: Sirona Dental Systems; 3M ESPE; Nobel Biocare; Henry Schein Inc. of Melville, N.Y.; Dentsply Implants of Waltham, Mass.; Dental Wings, Inc. of Montreal, Canada.
The crown or bridge can be very accurately fabricated and provide a consistent and unusually good fit to the tooth for much higher longevity than with manually prepared and fitted crowns. Manually prepared teeth and fitted crowns introduce human errors at several stages, from not creating the stone models correctly, not trimming the model dies correctly, to not casting the metal substructures accurately. Final fitting of the crown or bridge by the dentist will also determine if the restorations will achieve a high level of marginal fit.
Even with the availability of imaging and navigation systems, much of the manual work is still done by the dentist, e.g. tooth preparation is done by milling the tooth with a handheld mill at the risk of under/over cuts and possible injury to healthy tissue or enamel. The level of difficulty increases by a multiple for a dental bridge where multiple teeth in the mouth have to be milled in parallel with slight six degrees of taper to create a proper path of insertion. All of the teeth prepared for a dental bridge must share a common long axis ideally. Manual operations are lengthy procedures and cause appreciable discomfort and stress to the patients. It's also common in dental drilling and burring procedures to encounter zones of differing substrate hardness that causes the rotational speed of the tool to increase or decrease. This is usually caused when the instrument encounters softer or harder tissues in its path. If sensed and reacted to quickly, the dentist can either stop drilling into healthy enamel or proceed further to remove unhealthy tissue respectively. It is therefore desirable to have means to sense changes in the hardness of the tissue and automatically respond without relying on human senses and reaction. The dentist also can use his or her finger to feel and respond to occasional movements by the patient; a more reliable sensing means is, of course, advantageous.
In Orthodontic Treatment, such as the attachment of orthodontic braces brackets, the placement of the brackets has traditionally been done by mixing cement and placing it into the bonding surface of the bracket. Current cements are UV cured or self-curing. The amount of cement can vary and the excess cement must be removed manually without touching the bracket. Removal of the cement and accidentally moving the bracket in the process creates a source of positional error. The accuracy is dependent on the dexterity by the orthodontist. Inadequate metering of the cement adversely changes the position of the bracket.
Anesthesia is delivered in the form of a mandibular nerve block. The mandibular nerve has to be approximated by the dentist at the entry point of where it enters the mandible. The anesthesia then has to be manually delivered and if delivered too quickly, localized pressure from the anesthesia can produce discomfort to the patient.
For dental implants, CT Scanning and 3D modeling are commonly used in implant treatment planning and surgical guides are created by manufacturers. The surgical guides are placed directly on the soft gum tissue and stabilized by hand or guide pins placed into the bone. The gum tissue can move during surgery introducing errors. In dental bridges supported by multiple implants, all implants ideally must share a common long axis, or additional angulated parts, which are needed for connecting the angulations, thereby increasing treatment costs.
Current root canal treatment systems involve cleaning the internal canals in the root system to remove any infected tissue present. Laser treatment or other treatment modalities delivered through fiber optics can clean the canals in a radial and 3D manner that the reamer tools currently used cannot. The completion of the root canal is filling the canal with a sealant and gutta percha which is a rubber like material that fills the canal preventing bacteria from passing through the root system into the jaw bone. This gutta-percha is flowable when warmed to a determined temperature and solidifies into a solid 3D structure forming a comprehensive seal.
It's important to determine the depth of the apex and inject the warmed gutta percha material precisely to prevent extrusion of material through the apex or under-filling the canal by accident.
Oral Surgery Procedures: a tooth extraction is performed by pulling and elevation of a tooth under pressure. Occasionally, the dentist may have to drill the entire tooth from the socket with a risk of injury to vital structures such as a nearby nerve causing permanent nerve damage to the patient; a more reliable procedure is desirable.
However, the current support given to the medical and dental professional only provides enhanced visualization, a pre-planning platform, and monitoring means. The actual procedure is usually done by the professional either by remote control or physically by personally manipulating the instruments, or manipulating instruments with guides. This direct manipulation by the professional makes it subject to human errors and the limitations of the professional's skill and manual dexterity; manual accuracy is seriously limited and occasional mistakes and missteps do occur. Such mistakes may cause harm to the patient and sizable financial liabilities for patient, healthcare provider and insurer.
Direct manipulation of the instruments by the professional also demands appreciable care to mitigate the risk of mistakes and is inherently a slow process; it exposes the patient to increased stress as the procedure duration extends. This is especially critical for the metered delivery of drugs, such as anesthesia, that requires accurate metering of the rate of delivery and requires high level of experience.
Currently information associated with medical procedures is tracked locally in each treatment facility, mostly manually or with paper documents. Data of diagnoses, procedures, tools, materials, and outcomes are not usually communicated between treatment locations. This does not lend itself to data mining that may help practitioners share experiences, improve procedures and benefit patients from the data.
Delivery of materials, such as anesthetics, chemotherapy agents, require precise metering and location relative to anatomical landmarks. This is currently subject to indefinite identification of the location and human dexterity inaccuracies.
Soft tissue has anatomical mobile landmarks. Medical instruments and procedures, which interact with this soft tissue have issues of accuracy in locating the desired targets. Procedures such as drawing blood, spinal taps, and needle biopsies of tumors near vital structures, etc., require a high level precision and dexterity that are subject to uncertainty because of tissue mobility.
Most medical treatment procedures, especially surgeries, are performed by medical professionals manually according to pre-set plans for each procedure. The procedure is then carried out by the professional who depends on his/her experience and memory to either follow or modify the procedure during the treatment. There is much risk involved here especially if experience is lacking and decisions are made under pressure. This subjects the professional to appreciable stress in making serious decisions while the welfare of a human being is at stake.